I have a table like this:
ID | name
45 Alex
98 Diana
32 Peter
98 Daniel
45 Alex
23 Bob
98 Jake
I need to find all rows where is the same ID but different name.
You could use first/last value() window functions here:
with n as (
select *,
First_Value(name) over(partition by id order by (select null)) n1,
Last_Value(name) over(partition by id order by (select null)) n2
from t
)
select Id, Name
from n
where n1 != n2
You can use exists:
select t.*
from mytable t
where exists (select 1
from mytable t2
where t2.id = t.id and t2.name <> t.name
);
A windowed count is usually the most efficient:
SELECT
t.ID,
t.name
FROM (
SELECT *,
c = COUNT() OVER (PARTITION BY t.name)
FROM YourTable t
) t
WHERE c > 1;
SELECT
ID,
name,
CASE WHEN COUNT(ID) OVER(PARTITION BY ID) = 1 THEN 'OK' ELSE 'NOT OK' END AS CountID
FROM Table
GROUP BY ID,name
ORDER BY ID
Example:
Related
How can I only get the data with the same ID, but not the same Name?
The following is the example to explain my thought. Thanks.
ID Name Date
123 Amy 08/03/2022
123 Amy 12/03/2022
456 Billy 08/03/2022
456 Cat 09/03/2022
789 Peter 10/03/2022
Expected Output:
ID Name Date
456 Billy 08/03/2022
456 Cat 09/03/2022
How I have done.
select ID, Name, count(*)
from table
groupby ID, Name
having count(*) > 1
But the result included the following parts that I do not want it.
ID Name Date
123 Amy 08/03/2022
123 Amy 12/03/2022
One approach would be to use a subquery to identify IDs that have multiple names.
SELECT *
FROM YourTable
WHERE ID IN (SELECT ID FROM YourTable GROUP BY ID HAVING COUNT(DISTINCT Name) > 1)
I'd join the table to its self like this:
SELECT DISTINCT
a.Id as ID_A,
b.Id as ID_B,
a.[Name] as Name_A
FROM
Test as a
INNER JOIN Test as b
ON A.Id = B.Id
WHERE
A.[Name] <> B.[Name]
Do you want
SELECT * FROM table_name
WHERE ID = 456;
or
SELECT * FROM table_name
WHERE ID IN
(SELECT
ID
FROM table_name
GROUP BY ID
HAVING COUNT(DISTINCT name) > 1
);
?
Window functions are likely to be the most efficient here. They do not require self-joining of the source table.
Unfortunately, SQL Server does not support COUNT(DISTINCT as a window function. But we can simulate it by using DENSE_RANK and MAX
WITH DistinctRanks AS (
SELECT *,
rnk = DENSE_RANK(*) OVER (PARTITION BY ID ORDER BY Name)
FROM YourTable
),
MaxRanks AS (
SELECT *,
mr = MAX(rnk) OVER (PARTITION BY ID)
FROM DistinctRanks
)
SELECT
ID,
Name,
Count
FROM MaxRanks t
WHERE t.mr > 1;
I want to create a SQL query that SELECT a ID column and adds an extra column to the query which is a group number as shown in the output below.
Each group consists of 3 rows and should have the MIN(ID) as a GroupID for each group. The order by should be ASC on the ID column.
ID GroupNr
------------
100 100
101 100
102 100
103 103
104 103
105 103
106 106
107 106
108 106
I've tried solutions with ROW_NUMBER() and DENSE_RANK(). And also this query:
SELECT
*, MIN(ID) OVER (ORDER BY ID ASC ROWS 2 PRECEDING) AS Groupnr
FROM
Table
ORDER BY
ID ASC
Use row_number() to enumerate the rows, arithmetic to assign the group and then take the minimum of the id:
SELECT t.*, MIN(ID) OVER (PARTITION BY grp) as groupnumber
FROM (SELECT t.*,
( (ROW_NUMBER() OVER (ORDER BY ID) - 1) / 3) as grp
FROM Table
) t
ORDER BY ID ASC;
It is possible to do this without a subquery, but the logic is rather messy:
select t.*,
(case when row_number() over (order by id) % 3 = 0
then lag(id, 2) over (order by id)
when row_number() over (order by id) % 3 = 2
then lag(id, 1) over (order by id)
else id
end) as groupnumber
from table t
order by id;
Assuming you want the lowest value in the group, and they are always groups of 3, rather than the NTILE (as Saravantn suggests, which splits the data into that many even(ish) groups), you could use a couple of window functions:
WITH Grps AS(
SELECT V.ID,
(ROW_NUMBER() OVER (ORDER BY V.ID) -1) / 3 AS Grp
FROM (VALUES(100),
(101),
(102),
(103),
(104),
(105),
(106),
(107),
(108))V(ID))
SELECT G.ID,
MIN(G.ID) OVER (PARTITION BY G.Grp) AS GroupNr
FROM Grps G;
SELECT T2.ID, T1.ID
FROM (
SELECT MIN(ID) AS ID, GroupNr
FROM
(
SELECT ID, ( Row_number()OVER(ORDER BY ID) - 1 ) / 3 + 1 AS GroupNr
FROM Table
) AS T1
GROUP BY GroupNr
) AS T1
INNER JOIN (
SELECT ID, ( Row_number()OVER(ORDER BY ID) - 1 ) / 3 + 1 AS GroupNr
FROM Table
) T2 ON T1.GroupNr = T2.GroupNr
When I perform "SELECT * FROM table" I got results like below:
ID Date Time Type
----------------------------------
60 03/03/2013 8:55:00 AM 1
60 03/03/2013 2:10:00 PM 2
110 17/03/2013 9:15:00 AM 1
67 24/03/2013 9:00:00 AM 1
67 24/03/2013 3:05:00 PM 2
as you see each ID has a transaction Type 1 and 2 in the same Date
except ID 110 HAS only Type 1
So how could I just get result like this:
ID Date Time Type
----------------------------------
110 17/03/2013 9:15:00 AM 1
as only one record are returned from the first result
Change the partition definition (partition by id,date) according to your needs
select *
from (select t.*
,count(*) over (partition by id,date) as cnt
from mytable t
) t
where t.cnt = 1
;
You can use this:
select * from my_table t
where exists (
select 1 from my_table
where id = t.id
group by id
having count(*) = 1
)
If you want only type 1, then compare the minimum and maximum values. I prefer window functions:
select t.*
from (select t.*, min(type) over (partition by id) as mintype,
max(type) over (partition by id) as maxtype
from t
) t
where mintype = maxtype and mintype = 1;
If you want only records of the same type (and not specifically type = 1), then remove that condition.
If you want only records on the same day, then include the date in the partition by.
Under some circumstances, not exists can be faster:
select t.*
from t
where not exists (select 1 from t t2 where t2.id = t.id and t2.type <> 1);
If I have a table like this:
Id StateId Name
1 1 a
2 2 b
3 1 c
4 1 d
5 3 e
6 2 f
I want to select like below:
Id StateId Name
4 1 d
5 3 e
6 2 f
For example, Ids 1,3,4 have stateid 1. So select row with max Id, i.e, 4.
; WITH CTE AS
(
SELECT *, ROW_NUMBER() OVER(PARTITION BY STATEID ORDER BY ID DESC) AS RN
)SELECT ID, STATEID, NAME FROM CTE WHERE RN = 1
You can use ROW_NUMBER() + TOP 1 WITH TIES:
SELECT TOP 1 WITH TIES
Id,
StateId,
[Name]
FROM YourTable
ORDER BY ROW_NUMBER() OVER (PARTITION BY StateId ORDER BY Id DESC)
Output:
Id StateId Name
4 1 d
6 2 f
5 3 e
Disclaimer: I gave this answer before the OP had specified an actual database, and hence avoided using window functions. For a possibly more appropriate answer, see the reply by #Tanjim above.
Here is an option using joins which should work across most RDBMS.
SELECT t1.*
FROM yourTable t1
INNER JOIN
(
SELECT StateId, MAX(Id) AS Id
FROM yourTable
GROUP BY StateId
) t2
ON t1.StateId = t2.StateId AND
t1.Id = t2.Id
The following using a subquery, to find the maximum Id for each of the states. The WHERE clause then only includes rows with ids from that subquery.
SELECT
[Id], [StateID], [Name]
FROM
TABLENAME S1
WHERE
Id IN (SELECT MAX(Id) FROM TABLENAME S2 WHERE S2.StateID = S1.StateID)
I have this table
ID AGE ACCNUM NAME
--------------------------------
1 10 55409 Intro
2 6 55409 Chapter1
3 4 55409 Chapter2
4 3 69591 Intro
5 6 69591 Outro
6 0 40322 Intro
And I need a query that returns the two max age from each ACCNUM
in this case, records:
1, 2, 4, 5, 6
I have tried too many queries but nothing works for me.
I tried this query
Select
T1.accnum, T1.age
from
table1 as T1
inner join
(select
accnum, max(age) as max
from table1
group by accnum) as T2 on T1.accnum = T2.accnum
and (T1.age = T2.max or T1.age = T2.max -1)
TSQL Ranking Functions: Row_Number() https://msdn.microsoft.com/en-us/library/ms186734.aspx
select id, age, accnum, name
from
(
select id, age, accnum, name, ROW_NUMBER() Over (Partition By accnum order by age desc) as rn
from yourtable
) a
where a.rn <= 2
You can use row_number():
select accnum
, age
from ( select accnum
, age
, row_number() over(partition by accnum order by age desc) as r
from table1 as T1) t where r < 3
CODE:
WITH CTE AS (SELECT ID, AGE, ACCNUM, NAME,
ROW_NUMBER() OVER(PARTITION BY ACCNUM ORDER BY AGE DESC) AS ROW_NUM
FROM T1)
SELECT ID, AGE, ACCNUM, NAME
FROM CTE
WHERE ROW_NUM <= 2
Uses a common table expression to achieve the desired result.
SQL Fiddle